The invention relates to a storage arrangement comprising a channel for accommodating chip-like electronic components in predefined order and alignment.
German application laid open to public inspection 42 20 700 discloses a storage arrangement for electronic components, which comprises an, in essence, disc-like body in whose inside is arranged an, in essence, helical channel and an opening as a continuation of the helical channel, so that the channel is connected to the outside of the disc-like body. In the channel of this storage arrangement can be stored electronic components in a predefined order. For feeding the storage arrangement with electronic components, vibrations are applied to the storage arrangement and the components are supplied via a vibrating feeding arrangement. This storage arrangement may be designed such that it can be used as a feeding source for feeding the electronic components to a mounting head of an automatic mounting device for mounting the electronic components on printed circuit boards. For this purpose, the storage arrangement particularly has air supply holes which are connected to an air supply source through which the air is fed to the helical channel, so that the electronic components can be moved forward along the helical channel to the opening of the storage arrangement. The electronic components can then be taken out of the storage arrangement by means of the air supplied to the helical channel by the air supply source through the air supply holes.
Compared to a line-up of electronic components on so-called tapes or the like, such storage arrangements are advantageous in that they can be reused. They can be easily maintained and are mechanically robust.
However, it has appeared that maintaining the shape of the storage arrangement known from DE-OS 42 20 700 has several disadvantages. It is true, the disc-like configuration of the body of the storage arrangement according to DE-OS 42 20 700 has the advantage that, when placed on end, it requires only little space on a mounting device of the described type. In contrast to this, however, there is the disadvantage of the compulsorily diminishing channel radius from the opening of the channel to the inside of the storage arrangement, and the fact that this channel can be filled or emptied only through this single opening. In addition, different arrangements are necessary for filling and emptying, that is, on the one hand, a vibration device, and on the other, a compressed air device. The latter property alone already considerably increases the cost of maintenance of the known storage arrangement. The channel radius of the storage arrangement, which diminishes towards the inside of the disc-like body, may lead to the fact that electronic components that have certain outside dimensions, which can still without any obstruction be led to regions of the channel having a larger radius, can be moved only with difficulty or tend to jam in regions of the channel having a small radius. This may lead to problems during filling and, more particularly, during the emptying of the storage arrangement while the disc is being put in said mounting device.
It is an object of the invention to provide a storage arrangement for accommodating chip-like electronic components, by which arrangement the disadvantages of the known storage arrangement described above are eliminated.
This object is achieved according to the invention with a storage arrangement of the type defined in the opening paragraph, in that the channel for accommodating the components between a first and a second end is at least largely led along a helical line.
Whereas the radius of a helical channel along the longitudinal extension of this channel from the end of the channel compulsorily becomes ever smaller, the radius of a helical line can be adapted at will to the requirements. In this respect, a helical line is understood to be a spatial curve that can be described in the following manner in cylindrical co-ordinates comprising longitudinal co-ordinates, radius and angle of rotation:
The longitudinal co-ordinate is a monotonously increasing function of the angle of rotation, whereas the radius in the most general form of the thus defined helical line is a constant function of the angle of rotation, whose function values are always positive. Contrary to a spiral that expands in a plane, a helical line represents something three-dimensional. With such a helical line, the radius may be selected at will. A channel in the form of a helical line may then have over its entire length a radius that guarantees that the components can be aligned in predefined manner without an unwanted change and without being jammed. A channel in the form of a helical line may also be arranged to be accessible from either end and at the same time be monitored or observed over its entire length. As a result, the storage arrangement can be filled and emptied with the same direction of motion of the components in the channel. Irregularities during operation can be detected and eliminated more quickly and more easily. In addition, for example a first end of such a channel in the form of a helical line can be spatially arranged in a storage arrangement according to the invention in a simple manner with a second end of a second storage arrangement according to the invention, so that a simple transition of components is enabled between the channels of the two storage arrangements.
With such a helical line, the longitudinal co-ordinate of said cylindrical co-ordinates is also denoted a helical axis here.
For the connection of the channels of various storage arrangements according to the invention, that is to say, for the stackability, it is advantageous for the channel in the form of a helical line to have at least largely matching radiuses at its ends.
In an advantageous embodiment of the storage arrangement according to the invention, the channel is led, in essence, along a cylindrical helical line. A cylindrical helical line is understood to mean a helical line that is led at least in essence along the generated surface of a cylinder. A cylinder is then understood to be a body that is bounded by a cylinder surface with a closed directrix and two planes which, in essence, run in parallel. A cylinder surface is then understood to be the surface that is enclosed by a straight line, the so-called generatrix, when this generatrix glides along a curved, preferably closed line, the so-called directrix, without a change of its direction.
In the storage arrangement according to the invention, the described directrix of the cylinder surface along which runs the cylindrical helical line, may preferably have an elliptical or an oval shape. As a result, in a direction perpendicular to the helical axis the helical line can have a smaller diameter than in a second radial direction preferably directed perpendicular to the helical axis. In this manner a storage arrangement may be obtained with an enlarged storage capacity, without an enlargement of one of the dimensions perpendicular to the helical axis.
A very simply embodied storage arrangement according to the invention is obtained when the channel is led, in essence, along a circular cylindrical helical line. This circular cylindrical helical line stretches out along the generated surface of a circular cylinder. A channel embodied like this has the same radius at each position of a longitudinal extension and, with respect to the helical axis, also the same gradient or pitch, respectively. As a result, a thus designed storage arrangement cannot only be manufactured in a simple manner, but has at each position of the channel the same properties for the components stored therein. Consequently, highly favorable uniform conditions are created for the movements of the components in the channel, which conditions make handling of the components easier.
With a circular cylindrical helical line of this type, the directrix of the cylinder surface along which the helical line is led is formed by a circle whose center lies on the helical axis.
According to a further embodiment of the storage arrangement in accordance with the invention, the channel is connected to the exterior of the storage arrangement at least one of its ends by means of an opening. Preferably, an opening is provided at either end of the channel. A first one of these openings at the first end of the channel may preferably be used for filling the storage arrangement with components, whereas, advantageously, a second one of these openings at the second one of the ends of the channel is provided for unloading the components from the storage arrangement. The components then move inside the channel always from the first to the second opening. Thus, devices in which the storage arrangement can be filled can at least in essential features be equal to the devices that can be used for unloading the components from the storage arrangement. This implies a considerable simplification of the handling of the storage arrangement according to the invention.
At this point it is observed that from European patent application 0 108 401 is known a magazine for small electronic components, which magazine comprises a tubular body whose main part is wound to a spiral and whose end parts stretch out in axial direction of these spirals. The tubular body may be wound around a coil frame comprising a cylinder with two flange-like discs to which a respective trunnion is attached. The end parts of the tubular body are led out through openings in the flange-like discs and led to the inside of the trunnions, which at their respective ends have funnel-like openings to which bores are led ending up in the end parts. This magazine is particularly provided for storing diodes whose electrodes are formed by metal surfaces and which are arranged for direct soldering in printed circuits. These diodes comprise an isolating cylinder containing the semiconductor crystal and being closed by two metal parts whose surfaces are used as electrodes. Such a cylinder is first bonded to a printed circuit and then attached to the printed circuit board by wave soldering and fixedly connected to the circuit. Prior to the use of such components it is necessary for the cylinder to be aligned not only along its axis, but also in dependence on the polarity of the diodes. The tubular body is now constituted such that the electronic components flow through it and are guided so that they retain their alignment.
Such a magazine, which has a distinctly provisional shape and manufacture, proves to be unsuitable for storing chip-like electronic components as they are required by modem semiconductor technology. The tubular body of the known magazine only allows an alignment of the cylindrical components relative to their longitudinal axis. The alignment of chip-like components, however, also includes avoiding an indefinable rotation along such a longitudinal axis. With the known magazine, such a rotation or definition of position respectively is not a problem. Furthermore, there is a risk in the funnel openings of the trunnions that the stored components get out of the desired alignment at these places. In addition, on its end parts, but also along its main part, the tubular body has changing, undefined curvature radii which may turn out differently for the described provisional construction of the magazine from one storage arrangement to the next. This renders the carrying of components in the tubular body more unreliable than in the in essence helical channel as described in DE-OS 42 20 700. Furthermore, since the tubular body is wound on the coil frame, at least several sections of the main part of the tubular body may no longer be accessed from the exterior. If irregularities then occur in the undefined curvature radii described above when the electronic components are carried along through the tubular body, possibly these irregularities, for example, jammings can only be remedied at great expense, possibly only by destroying the tubular body.
In addition, on account of its provisional construction, the manufacture of the magazine known from EP 0 108 401 A2 is not only more expensive than the manufacture of the storage arrangement according to the invention, which can be effected in a very simple and cost-effective manner with manufacturing means for industrial scale manufacture, but the known magazine also has a bulky shape which is unfavorable when handled on modern semiconductor arrangements.
In a preferred further embodiment of the storage arrangement according to the invention, this storage arrangement has a first base-like projecting portion in the region of the first end of the channel and a second base-like projecting portion in the region of the second end of the channel, which base-like projecting portions are each other""s complement, and the second base-like projecting portion of a first storage arrangement can be joined to the first base-like projecting portion of a second storage arrangement for connecting the second opening at the second end of the channel of the first storage arrangement to the first opening at the first end of the channel of the second storage arrangement for the components to pass through.
Via these base-like projecting portions, each time two storage arrangements according to the invention can be coupled to each other in a very simple manner. As a result, the storage capacity can be increased or the components may be put from one storage arrangement into another storage arrangement.
In a further embodiment of the storage arrangement according to the invention, the channel is led over its entire length along a circular cylindrical helical line. The pitch of this circular cylindrical helical line has an in essence first value between the regions around the ends of the channel. In the regions of the ends of the channel, the pitch has a second value, which is higher than the first value of the pitch. In the regions of the ends, the mutual distance of the turns of the channel is increased by the increased pitch. This enables a robust construction of the storage arrangement according to the invention, which is insensitive to mechanical damage when the base-like projecting portions are combined. Between the regions around the ends of the channel, however, its turns should be as close together as possible, in accordance with an extremely small first value of the pitch to keep the storage capacity of the storage arrangement as large as possible for predefined overall measurements. Nonetheless, the shape of the channel which is essential to the invention will be kept in accordance with a helical line also in the regions of the ends of the channel. This guarantees here too a precise handling of the chip-like components. This is a great advantage for the coupling of the storage arrangement according to the invention, for example, to a second storage arrangement.
In another embodiment of the storage arrangement according to the invention, in which the channel is led over its entire length along a cylindrical helical line, this storage arrangement has a construction with a cylindrical inner body and a cylindrical outer body. The inner body has an outside generated surface with which it is inserted into the outer body along an inside generated surface of the outer body. The generated surfaces of the inner body and of the outer body at least largely have mutually adapted contours.
An assembly of this type can easily be manufactured. It also enables to manufacture the channel in a very simple manner when the latter, in an advantageous further embodiment, is embedded in the inner body at least largely along the outside generated surface of the inner body. More particularly the lands of the channel may be embedded in the inner body in three directions perpendicular to the longitudinal extension of the channel, whereas the inside generated surface of the cylindrical outer body forms an edge of the channel in the fourth direction perpendicular to the longitudinal extension of the channel. It is very simple to manufacture such a construction in large volumes by injection molding in an accurate, cost-effective manner. Also other manufacturing methods or other materials can be used without further measures being taken.
In a further embodiment of the storage arrangement according to the invention, the first and second base-like projecting portions are at least to a considerable extent adapted to the inner body. In this manner the base-like projecting portions and the channel always have a defined position relative to each other, irrespective of tolerances or irregularities during manufacturing or handling of the storage arrangement.
According to a further embodiment, the outer body of the storage arrangement according to the invention is formed at least in sections of an at least largely transparent material. This enables a fast, simple survey of the channel, so that filling level or irregularities during operation can be recognized fast and reliably with the storage arrangement according to the invention. An embodiment described above with an inner body and an outer body furthermore enables a fast access to any position of the channel.
Advantageously, the openings at the ends of the channel of the storage arrangement according to the invention have each a locking element for locking the channel to avoid components included therein coming out. Preferably, these locking elements may be spring-mounted, which enables forming these elements in a simple way. Advantageously, each base-like projecting portion has its own actuating element by which the locking element in the area of the complementarily arranged base-like projecting portion of a further storage arrangement can be actuated when these two storage arrangements are connected by the opening of the channel. Co-operation between such an actuating element of a first storage arrangement and a locking element of a second storage arrangement then occurs when the two storage arrangements are joined by their complementary base-like projecting portions. The combination then automatically actuates the locking element, so that the channel is opened. More particularly the actuating elements of the two storage arrangements simultaneously influence, the locking elements of the respective other storage arrangement within the range of the joined base-like projecting portions. When the two storage arrangements are coupled, the two locking elements are opened simultaneously; when the two storage arrangements are separated, the two locking elements automatically again simultaneously close the openings of the channels. Without additional operating steps, a loss of components is bound to happen.
Preferably, the base-like projecting portions of the storage arrangement are arranged, in essence, as a bayonet catch. This enables a fast and uncomplicated joining and separation of storage elements.
The storage arrangement according to the invention can in a simple-structured and reliable device be filled with components and the components can also be unloaded therein from the storage arrangement. Such a device advantageously includes a first sub-assembly preferably for filling the storage arrangement with components. The first base-like projecting portion of the storage arrangement can be coupled to this first sub-assembly. The first sub-assembly has a feeding element arranged in the form of a channel, which can be aligned to the first opening of the channel of the storage arrangement. Via the feeding element the components can then be inserted into the channel through the first opening and the storage arrangement can be filled in this manner. Preferably, for this filling operation the feeding element has an essentially linear vibrating movement. The feeding element is therefore advantageously coupled to a first vibration device arranged for such a movement. More specifically, such a vibration movement working together with gravitation is exerted on the components to be moved. For this purpose, the feeding element may have an inclination in the direction to the first opening of the storage arrangement. Advantageously, also the storage arrangement is brought to a position in which the channel has a similar inclination. This is preferably attained by installing the storage arrangement with an essentially perpendicular helical axis. In addition, the storage arrangement may be actuated by an essentially radial vibration movement, which will be reverted to hereinafter.
A device for handling the storage arrangement according to the invention may, preferably for unloading the components, be arranged such that the second base-like projecting portion of the storage arrangement can be coupled to a second sub-assembly. This second sub-assembly of a device arranged in this way has a channel-like discharge element which, for unloading the components from the storage arrangement, can be aligned to the second opening of the channel of the storage arrangement.
Since the discharge element, on the one hand, and the feeding element, on the other, are coupled to two different openings of the storage arrangement, components in the device can be put into the storage arrangement and also unloaded therefrom. This allows a highly flexible, variable handling of the storage arrangement according to the invention.
Preferably, a device of said type has a base-like projecting portion whose embodiment for accommodating the second base-like projecting portion of the storage arrangement at least largely corresponds to the shape of the first base-like projecting portion of this storage arrangement. This base-like projecting portion of the device provides an alignment of the second opening of the channel of the storage arrangement to the discharge element. The base-like projecting portion of the device thus, on the one hand, provides the mechanical support of the storage arrangement when handled for unloading the components and at the same time guarantees their flawless transition from the channel through the second opening into the discharge element. A uniform design of the base-like projecting portions may provide that any storage arrangement can be coupled to the device and also joined to each other. As a result, a plurality of storage arrangements can be cascaded to the device at the same time in such a way that their channels can be passed through in succession and with the discharge element can be passed through continuously.
With a device of the type described above, the base-like projecting portion of this device and the discharge element can be jointly coupled to a second vibration device. This second vibration device is advantageously arranged, in essence, for a radial vibration movement. In this design the device has a very simple, compact construction.
Also for transporting the components within the discharge element, a co-operation between the vibration movement and the influence of gravity may be used to advantage.
In a variation of the device, separate vibration devices can be provided for the discharge element, on the one hand, and the base-like projecting portion of the device, on the other. A radial vibration movement is then preferred for the base-like projecting portion, preference being given to a radial vibration movement which is imposed on this base-like projecting portion by means of an accordingly designed vibration device. A further vibration device which is, in essence, designed for a linear vibration movement, is then separately connected to the discharge element. This slightly more expensive construction, however, alternatively makes it possible to design the discharge element with a larger length and smaller slope i.e. a smaller influence of gravity.
For a storage arrangement in which the openings of the channel have each a locking element for closing the channel to avoid components included therein escaping, the base-like projecting portion of the device may have an actuating element by which the locking element in the region of the second opening of the channel of the storage arrangement can be actuated in that the channel is opened, when the second base-like projecting portion of a storage arrangement designed in said manner is joined to the base-like projecting portion of the device. When the storage arrangement is coupled to the device, the opening of the channel for allowing the components to pass in the direction of the discharge element is released automatically in the same manner as when two such storage arrangements are coupled.
An advantageous further embodiment of the described device includes a stop device for interrupting the feeding of components from the channel of a coupled storage arrangement. Such a stop device, which works independently of the actuation of the locking elements of the storage arrangement, is advantageously used for interrupting the feeding of components in the storage arrangement still coupled to the device. For example, this stop device can interrupt the feeding of components to prepare the separation of the storage arrangement from the device. This provides the possibility of removing components from the region of the channel opening, preferably from the region of the second opening, for example, in that the discharge element is further operated over a predefinable period of time depending on the destination as agreed, prior to the storage arrangement being removed from the device. This avoids an uncontrollable loss of components and a disturbance as a result of components leaving the channel opening in uncontrolled manner.
A particularly simple and manageable as well as robust embodiment of the base-like projecting portions of the device and of the storage arrangement is achieved in that the base-like projecting portion of the device is arranged in similar fashion to the base-like projecting portions of the storage arrangement by way of a bayonet catch. A bayonet catch design of the base-like projecting portions is especially suitable in that, conventionally, there are regions on these base-like projecting portions which determine a brief screw-like installing movement. These regions, however, can be advantageously arranged at little expenditure so that, in addition to a flexible coupling, they also guarantee a very precise alignment of the storage arrangement in the device and thus a very precise alignment of the channel openings of this storage arrangement. A precise positioning of the storage arrangement in operation in spite of very simple handling is thus guaranteed in a simple manner.